Counterbalance crank



N v. 11, 1941... H. R} HOGABOQM 2,2 2, 3

COUNTERBALANCE CRANK Filed Sept. 30, 1940 INVENTOR- ATTORNEYS.

terbalance crank.

Patented Nov. 11, 1941 PATENT OFFICE ;.ooUNrER ALANE CRANK Henry R. Hogaboom, .GlendalaCaliL, assignorto Pacific Gear & Tool Works, Inc., Los Angeles, Calif., a corporationof California Application September so, 1940, Serial No. 359,052

. crank-shaftand keyed in positionis a counterweight sector I] having an arcuate marginal 7 Claims. This invention relates to -oil .wellipumping equipment and particularly pertains to a coun In the operation of oil well pumping equipment it is usual practice to providea structure having a walking beam carried uponya king post and adapted to oscillate vertically,one end of the beam being fitted with a horsehead'to which the pump string is connected and the other end of the beam being oscillated by rotary power driving means. ,Due' to load variation conditions on the up and down stroke of the pump rod, as determined by varying sets of factors,

it is necessary to provide means by which variation in power demand uponthe driving mechanism may be compensated, which'is usually accomplished by some type of counter-weight subject to angular adjustment or weight displacement. In many instances these structures are complicated in construction; require the movement of heavy weights and the inconvenient operation of various types of fastening means. It is the principal object of the present invention, therefore, to provide a counter-weight of the type disclosed, which carries *a crank arm de- .struction, easily applied and interlocked, and

instantly locked into position by removable and adjustable locking means.

edge 12. concentric with the axis of the shaft ,l0.- This marginal edge, as particularly shown in Fig. 2 of thedrawing, is formed with a portion of T- -section l3 connected to the main body portion M by a relatively narrow intermediate portion 15. This forms channels I6 along opposite sides of the crank throw sector II which provide trackways. for counterweight sectors l1. These sectors are formed with a T-shaped channel 18 which receives the portions 13 and I5 of the crank throw sectors and makes it possible for the counterweight sectors l! to be readily assembledon the crank throw sector. The opposite side faces 19 of the crank throw sector l-l' lie along radial planes emanating from the axis of the shaft l0. It will be seen that by this arrangement the sectors Il may be made of relatively light weight so that they may be .easily handled and placed in position or removed. therefrom. The counterweight sectors are, therefore, easily placed in position without the use of any individual fastening means. The contiguous weights areinterlocked by protrusions 20 extending from one side of each of theweights The present invention contemplates the provision of a crank throw sector, which is :secured upon a crank-shaft and rotates therewith, said the structure as seen on the line 2-2 of Fig. 1 and shows the manner in which the sectors are and projecting .into complementary recesses formed in the opposite side. These elements are substantially rectangular in shape. A center .lug

. 22 is formed intermediate the arcuate length of y,

the members l3 and I5 so that the counterweight sectors may belarrangedat each side of it.

removably mounted upon the counterweight sector.

Fig. 3 is a view in transverse section through one ofthe lock elementsindicating a fragmentary portion of the counterweight sector.

Referring more particularly to the drawing, 10 indicates a crank-shaft which is driven by suitable driving mechanism with which the pres- ;ent invention is not concerned. Mounted on .this

" Whena desired number of counterweight sectors have been mounted upon the crank throw sector they may be instantly locked in position by the locklelements 2,3. ,These elements have opposite side plates. and an :-end plate 25. The end plate 25is disposed radially of the crank throw sector and .abuts againstlthe outermost counterweight sector. Formed integral with the side and endplates isan arcuate portion 26 which conforms to the outer arcuate face of the member l3 on the crank throw sector. The

side plates 2 l provide a T-eshaped channel within which the portions L3 and I5 of the crank throw .fits and along which the locking elements may slide. Formed within the circumferential face of the portion l3 of the crank throw and in proper spaced relation to each other therealong are lock seats 2-! which receive a lock pin 28, one of which is carried by eachof the lock elements. These pins extend through a bore 29 in the portion 26 :and are yieldably held by spring blades .30. Thespring blades 30 are set into the poritions 25 0f the lock elements, as shown in Fig. 3.

The outer ends of these members are fitted with a knob 3i which permits the pin 28 to be drawn in and out of the recess 21. The spring blades 30 will act to yieldably hold these pins in position.

It will thus be seen that after a selected number of counterweight sectors have been mounted upon the crank throw sector at opposite sides of the stop lug 22 the locking elements 23 are slid onto the arcuate edge of the crank throw sector, and when in proper abutting relation against the outermost counterweights will be in a position to cause the lock pins 28 to find their way into the openings 21 as urged by the spring blades 30. The end plates 25 of the'locking elements 23 are each formed with a threaded boss 32 through which a cap screw 33 may be screwed to exert pressure against the outermost faces of the assembled group of counterweight sectors.

It will thus be seen that by the construction I here disclosed it is possible to quickly assemble a desired number of counterweight sectors upon the crank throw sector to meet the requirements of a particular condition and to thereafter instantly lock the counterweight sectors in position by simple and positive means without the use of bolts, screws or other similar fastening means. It will also be recognized that when counterweight sectors are to be added to the group used or removed therefrom that the looking elements 23 may be conveniently released from their set positions. Furthermore, the present invention provides convenient means for interlocking the counterweight sectors with the crank throw sector and in interlocking the various counterweight sectors with each other so that they will be held in alignment in a common plane.

When the structure has been assembled with the required number of weights and the locking means in position the cap screws 33 may then be tightened. This will forcefully hold the counter-weight sectors against each other and will maintain the protrusions 20 on the sides of the tor and whereby the counterweight sectors and the crank throw sectors may be assembled in interlocked relation, means on adjoining faces of the counterweight sectors whereby said sectors may be interlocked with relation to each other, and removable latch members adapted to be mounted on the T-portion of the crank throw and engaging the same to hold the counterweight sectors in fixed relation to the crank throw sector.

3. A counterweight for a rotating shaft comprising a crank throw sector having an arcuate edge concentric with the shaft, said edge being of T-section, a plurality of counterweight sectors formed at their inner ends with channel grooves to receive the T-section of the crank throw sector and whereby the counterweight sectors and the crank throw sectors may be assembled in interlocked relation, means on adjoining faces of the counterweight sectors whereby said sectors may be interlocked with relation to each other, and removable latch members adapted to be mounted on the T-portion of the crank throw and engaging the same to hold the counterweight sectors in fixed relation to the crank throw sector, said lock means including a pin yieldably held to engage the crank throw sector.

4. A counterweight structure for rotary shafts,

including a crank throw fixed to said shaft and counterweights seated within the complementary recesses of the next adjoining counterweight.

While I have shown the preferred form of my invention as now known to me, it will be understood that various changes may be made in combination, construction and arrangement of parts by those skilled in the art, without departing from the spirit of my invention as claimed.

latch members carried by said lock elements to engage the crank throw sector and to hold the counterweight sectors in their assembled position with relation to each other and the crank throw sector.

2. A counterweight for a rotating shaft com- I prising a crank throw sector having an arcuate edge concentric with the shaft, said edge being of T-section, a plurality of counterweight sectors formed at their inner ends with channel grooves to receive the T-section of the crank throw sec-- having an arcuate outer edge concentric with the axis of the shaft, said arcuate outer edge being of T-section, whereby a pair of grooves will be formed in the opposite side faces of the crank throw and concentric with said arcuate edge, a plurality of counterweight sectors formed with a channel across their inner ends, the channel conforming in section to the T-section of the crank throw and fitting into the grooves at opposite sides thereof, whereby the crank throw sector and the counterweight sectors may interengage and the counterweights may be moved along the arcuate portion of the crank throw sector, recesses formed at spaced intervals along the arcuate portion of the crank throw, locking elements to be disposed at opposite ends of the group of counterweight sectors mounted upon the crank throw sector, said locking means being formed with channel portions conforming to the T-shaped edge of the crank throw sector whereby the locking means may engage the crank throw sector and may be moved therealong to a position of abutment against the outermost faces of the group of counterweight sectors assembled on the crank throw, and yieldable latch means carried upon the locking elements to engage the recesses formed on the crank throw sector and whereby the locking means will be held against movement while holding the group of counterweight sectors in fixed position upon the crank throw;

5. A counterweight structure for rotary shafts, including a crank throw fixed to said shaft and having an arcuate outer edge concentric with the axis of the shaft, said arcuate outer edge being of T-section, whereby a pair of grooves will be formed in the opposite side faces of the crank throw and concentric with said arcuate edge, a plurality of counterweight sectors formed with a channel across their inner ends, the

channel conforming in section to the T-section of the crank throw and fitting into the grooves at opposite sides thereof, whereby the crank throw sector and the counterweight sectors may interengage and the counterweights may be moved along the arcuate portion of the crank weight sectors mounted upon the crank throw sector, said locking means being formed with channel portions conforming to the T-shaped edge of the crank throw sector whereby the looking means mayengage the crank throw sector and may be moved therealong to a position of abutment against the outermost faces of the group of counterweight sectors assembled on the crank throw, and yieldable latch means carried upon the locking elements to engage the recesses formed on the crank throw sector and whereby the locking means will be held against movement while holding the group of counterweight sectors in fixed position upon the crank throw.

6. A counterweight structure for rotary shafts, including a crank throw fixed to said shaft and having an arcuate outer edge concentric with the axis of the shaft, said arcuate outer edge being of T-section, whereby a pair of grooves will be formed in the opposite side faces of the crank throw and concentric with said arcuate edge, a plurality of counterweight sectors formed with a channel across their inner ends, the channel conforming in section to the T-section of the crank throw and fitting into the grooves at oppositesides thereof, whereby the crank throw sector and the counterweight sectors may interengage and the counterweights may be moved of the group of counterweight sectors assembled on the crank throw, and yieldable latch means carried upon the locking elements to engage the recesses formed on the crank throw sector and whereby the locking means will be held against movement while holding the group of counterweight sectors in fixed position upon the crank throw, said latch means comprising. a pin carried by the locking element and yieldably urged into a recess.

7. A counterweight structure for rotary shafts, including a crank throw fixed to said shaft and having an arcuate outer edge concentric with the axis of the shaft, said arcuate outer edge being of T'-section, whereby a pair of grooves will be formed in the opposite side faces of the crank throw and concentric with said arcuate edge, a

plurality of counterweight sectors formed with a channel across their inner ends, the channel conforming in section to the T-section of the crank throw and fitting into the grooves at opposite sides thereof, whereby the crank throw sector and the counterweight sectors may interengage and the counterweights maybe moved along the arcuate portion of the crank throw sector, recesses formed at spaced intervals along the arcuate portion of thecrank throw, locking elements to be disposed at opposite ends of the group of counterweight sectors mounted upon the crank throw sector, said locking means being formed with channel portions conforming to the T-shaped edge of the crank throw sector whereby the locking meansv may engage the crank throw sector and may be moved therealong to a position of abutment against the outermost faces of the group of counterweight sectors assembled on the crank throw, yieldable latch means carried upon the locking elements to engage the recesses formed on the crank throw sector and whereby the locking means will be held against movement while holding the group of counterweight sectors in fixed position upon the crank throw, and adjustable means for tightening the counterweight sectors with relation to each other and the lock means.

HENRY R. HOGABOOM. 

